The present invention relates to an antenna aiming system for facilitating wireless communication between wireless network devices. More particularly, the present invention facilitates identifying a particular signal being transmitted by a wireless communication device and then automatically adjusting the position of a receiving antenna to improve connectivity between wireless network devices.
Broadband Wireless Access (BWA) is a technology that uses radio frequency signals to provide network connectivity either between two points (sometimes called “backhaul”) or in a point to multi-point configuration that provides multiple users connectivity based on a wireless connection to a central device or access point. These wireless links typically either provide a high throughput connection to the Internet (usually over 2 Mbps), or access to other traditional computer networks without using wired connections.
The antennas used to provide the communication links between the BWA devices fall into two main categories. A first category is an omni-directional antenna which radiates in all directions. The second category is a directional antenna which is pointed in one direction and includes a concentrated signal beam. Omni-directional antennas do not need to be aimed, since they generally provide 360 degrees of coverage. However, omni-directional antennas provide a small coverage area, typically of only about 3-4 miles. Directional antennas can cover much longer distances, such as, for example, about 40 miles. However, the directional antennas must be aimed in order to establish a communication link. Typically, such aiming is done manually. Often an operator must climb a tower to adjust the antenna in order to receive the desired signal.
The present invention provides an automated aiming device that combines the best characteristics of both the omni-directional antenna and the directional antenna for use with BWA devices. The present invention automatically aims a directional antenna to maximize strength of the signal received from the transmitting antenna. The present invention can be used with two stationary antennas or with remote mobile antennas at a much greater distance than conventional omni-directional antennas. Therefore, the present invention permits coverage over larger areas, without the requirement of manually aiming the antennas.
The illustrated embodiments of the present invention provide a system for initializing and maintaining a functional radio connection between two or more BWA devices. Examples of such devices include, but are not limited to, the Motorola Canopy™ system, IEEE 802.16 standards based equipment, and IEEE 802.11 systems. In an illustrated embodiment of the invention, the aiming system uses a stepper and/or servo motor mechanism to manipulate the position and direction of the antenna relative to a transmitter such as an Access Point (transmitter/receiver supporting connectivity to multiple subscriber units) and/or a Subscriber Unit (client-end transmitter/receiver). The system includes software (or other electronic control system) that receives, evaluates, and responds to a radio signal, thereby automatically orienting the wireless connection points for broadband wireless communication. Functionally, the illustrated system includes an antenna mounted on or in a device that may mechanically reposition the antenna for the purposes of initializing and maintaining broadband wireless communication. The system also includes a software (or electronic) control process that monitors the strength and quality of antenna reception (as a function of the fixed or variable position of the antenna) and responds by positioning or repositioning the antenna to initialize and/or maintain broadband wireless communication.
In one illustrated embodiment, the system for initializing and maintaining a functional connection between two or more BWA devices receives input from the radio device via the audible tone jack that is present on the radio device, via a Simple Network Management Protocol (SNMP) interface on the radio device, via a “Screen Scraper” utility used to pull information from the configuration utility on the radio devices, or via some combination of these methods. In this embodiment, the system first alters the position of the antenna while monitoring the signal strength of a distant transmitter until the optimal antenna position has been identified (or all possible antenna positions have been surveyed), then uses this information to position the antenna for broadband wireless communication. Maintenance of the broadband wireless communication involves occasionally or persistently monitoring signal strength and then repositioning the antenna to facilitate constant broadband wireless communication. In the absence of radio signal, or if the signal is disrupted, the aiming system continues to alter the position of the antenna while monitoring the signal strength of a distant transmitter until the optimal antenna position has been identified (or all possible antenna positions have been surveyed). The aiming system then uses this information to position the antenna for broadband wireless communication. Other embodiments may include the use of other radio-direction support such as magnetometers, or GPS receiver assistance, or a combination of these technologies, as well as the utilization of algorithms (or other dedicated control systems) that project future optimal position(s) of the antenna based on changes in signal strength location(s).
The system for initializing and maintaining a functional connection between two or more BWA devices automatically aims the antenna devices, without direct human intervention, that cover a range that requires use of a directional antenna.
This aiming includes, but is not limited to moving the antenna device rotationally (horizontally or azimuth) and/or vertically (elevation), as well as the ability to change the location of the entire aiming system and antenna, or any combination thereof.
The system of the present invention may be used in many distinct classes of operation, in all of which BWA connectivity is used to provide wireless network connections to a location that then provides wired access connectivity to the Internet or other network resources. Illustratively, the aiming system of the present invention may be used for:
(1) initializing and maintaining a functional connection with stationary aiming of devices on towers or high-sites (often called back hauls);
(2) initializing and maintaining a functional connection with manned or unmanned vehicles that are in constant or occasional motion including, but not limited to seafaring, aviation, terrain, recreation, agriculture and military vehicles;
(3) initializing and maintaining a functional connection with low-mobility applications that require that a mobile vehicle such as a tractor, boat, or military vehicle which need to be tracked from a distance as they move; and
(4) high-mobility applications where a vehicle or aircraft must be tracked from a distance, possibly acting as a repeater to provide “down-beam” wireless network connectivity.
In addition, a system for initializing and maintaining a functional connection between two or more BWA devices will support communications with vehicles, devices and/or detectors positioned in or on unstable or dynamic hydrological or geological terrains including, but not limited to, lava flows, tidal pools, fault lines, mud slides, icebergs, glaciers, and aquatic surfaces.
In an illustrated embodiment, a method is provided for aiming an antenna to permit communication with a remote broadband wireless communication device. The method includes moving the antenna along a path, determining a signal quality value of a signal transmitted by the broadband wireless communication device and received by the antenna at a plurality of different locations along the path, storing the determined signal quality values and the associated antenna coordinates, selecting an optimal antenna position based on the stored signal quality values and the associated antenna coordinates, positioning the antenna at the selected optimal antenna position, and establishing a communication session between the antenna and the remote broadband wireless communication device.
The illustrated method further includes determining whether a trigger event has occurred, moving the antenna along an optimization scan path in an area adjacent the optimal antenna position upon occurrence of the trigger event, determining a signal quality value of a signal transmitted by the broadband wireless communication device and received by the antenna at a plurality of different locations along the optimization scan path, determining whether a new optimal antenna position exists based the signal quality values along the optimization scan path, and positioning the antenna at the new optimal antenna position upon determining that a new optimal antenna position exists.
In another illustrated embodiment, a method is provided for aiming an antenna to communicate with a broadband wireless communication device. The method includes using a first antenna including a receiver to determine an optimal antenna position by monitoring a signal quality value of a signal transmitted by the broadband wireless communication device and received by the first antenna at a plurality of different locations along a scanning path of the first antenna, positioning a second antenna including a receiver and a transmitter at the optimal antenna position, and establishing a communication session between the second antenna and the broadband wireless communication device.
In an illustrated embodiment, the step of using a first antenna including a receiver to determine an optimal antenna position includes moving the first antenna along a path, determining a signal quality value of a signal transmitted by the broadband wireless communication device and received by the first antenna at a plurality of different locations along the path, and selecting the optimal antenna position based on the signal quality values and the associated first antenna coordinates determined in the determining step. The illustrated method further includes continuously repeating the moving, determining and selecting steps to determine whether a new optimal antenna position exists during the communication session between the second antenna and the broadband wireless communication device, and moving the second antenna to the new optimal antenna position if the optimal antenna position has changed.
In another illustrated embodiment, a system is provided for aiming an antenna to communicate with a broadband wireless communication device. The system includes an antenna, a drive mechanism coupled to the antenna, and a controller coupled to the drive mechanism. The controller is configured to actuate the drive mechanism to move the antenna along a path. The controller includes means for determining a signal quality value of a signal transmitted by the broadband wireless communication device and received by the antenna at a plurality of different locations along the path, means storing the determined signal quality values and the associated antenna coordinates, means for selecting an optimal antenna position based on the stored signal quality values and the associated antenna coordinates, means for positioning the antenna at the selected optimal antenna position, and means for establishing a communication session between the antenna and the remote broadband wireless communication device.
Additional features of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.